import pandas as pd

tradedays = pd.DataFrame(data={'20211231': [16.86, 16.48, -0.34],
                               '20211230': [16.76, 16.82, 0.07],
                               '20211229': [17.16, 16.75, -0.42],
                               '20211228': [17.22, 17.17, -0.05],
                               '20211227': [17.33, 17.22, -0.09]},
                         columns=['open', 'close', 'change'],
                         index=['trade_date'])
print(tradedays)
